4AminoSensor is a rapid assay in dipstick format detecting the contamination of milk samples by aminoglycosides molecules. This kit is specific for Neomycin, Gentamycin, Kanamycin and (Dihydro)-Streptomycin detection.
4AminoSensor is a competitive test involving generic and specific antibodies in one single operation.
The test requires the use of two components. The first component is a microwell containing predetermined amounts of specific antibodies with high affinity for Neomycin, Gentamycin, Kanamycin and (Dihydro)-Streptomycin molecules, linked to gold particles. The second component is a dipstick made up of a membrane with three capture zones : a "control" line and the specific test lines placed below and above the control line.
For a valid test, the red control line in the middle has to be visible after the second incubation. The line for Neomycin / Gentamycin / Kanamycin is located above the control line while the line relating to Dihydro- and Streptomycin is located below the control line. When the reagent from the microwell is re-suspended with a milk sample, all antibodies will bind the corresponding analytes if present during the first 3-minute incubation at 40°C. Afterwards, when the dipstick is dipped into the milk, the liquid starts running vertically on the dipstick and passes through capture zones. When the sample is free of antibiotics, a colour development occurs at the specific capture lines, indicating the absence of the targeted analytes in the milk sample. On the contrary, the presence of antibiotics in the sample will not cause any coloured signal to appear at the specific capture lines.
Aminoglycosides are one of the major classes of antibiotics used in veterinary medicine to treat animal infections. They are especially effective against gram negative bacteria and are frequently used alone and in association with other antibiotics under intramammarry administration to treat mastisis of dairy lactating cows. The detection of residual antibiotics such as Aminoglycosides in milk is of great concern to farmers, milk industry, regulatory agencies and consumers. The consumption of Aminoglycosides can indeed have several adverse effects (allergic reactions, nephrotoxicity and ototoxicity) and may induce the emergence of multi-resistant bacteria that does not respond to commonly used treatments for human illnesses.
Although some microbial inhibition screening tests have a broad spectrum of antibiotics detection in milk, they are usually unable to detect Aminoglycosides at their European Maximum Residue Limit (MRL) concentrations. In contrast, some existing immunoassays such as ELISA are very sensitive but are time-consuming and specific for only one single Aminoglycoside compound due to the very limited structural similarities between the members of this antibiotic family.